Augmentative effect of polyethylene glycol, polyvinyl alcohol and dextran on thyroid-stimulating antibody stimulated cAMP production in FRTL-5 cells and CHO cells expressing human TSH receptor

Previously we reported the augmentative effect of non-ionic hydrophilic pol ymers such as polyethylene glycol (PEG), polyvinyl alcohol (PVA) and dextra n on thyroid-stimulating antibody (TSAb) activity in porcine thyroid cell a ssays. We examined whether a similar phenomenon occurs in FRTL-5 thyroid ce lls and CHO cells expressing the human (h)TSH receptor (CHO-hTSHR cells). A s with porcine thyroid cells, PEG 22.5% precipitated crude IgG from serum o f patients with Graves' disease, significantly increased cAMP production as compared with PEG 12.5% precipitated crude IgG in both FRTL-5 cells and CH O-hTSHR cells. PEG 5% augmented purified-TSAb-IgG-stimulated cAMP productio n in both cell assays. TSAb activities and positivity by the direct assay u sing whole serum (0.05 ml) in the presence of 5% PEG in untreated Graves' p atients were significantly increased as compared with the absence of 5% PEG . The augmentative effects of PVA 10% or dextran T-70 10% on TSAb-IgG-stimu lated cAMP production were also observed in both cell assays. PVA 10% did n ot augment TSH-stimulated cAMP production in spite of weak augmentation by dextran 10% in both cell assays. Lack of the augmentative effects of PEG 5% , PVA 10% and dextran 10% on cAMP produced by GTP gamma S, forskolin and pi tuitary adenylate cyclase activating polypeptide was observed in both cell assays. The augmentative effects of these polymers in both cell assays simi lar to porcine thyroid cells suggest that there is no apparent species spec ificity among human, porcine and rat thyroid cells as far as TSH receptor l inked cAMP production in cell membranes existed. Copyright (C) 2000 S. Karg er AG, Basel.